seat belts locked up

I have an 07 silverado that was in an accident. The front seat belts are strung tight and will not release. Is there a way you can release the tension on the seat belt without cutting the belt itself. Also, is it possible to re-use the seat belt.

anytime a seatbelt is in question other than being dirty, replace the seatbelt. insurance should have covered that and the body shop should have replaced them.....provided it has been there in the first place, but would replace them no questions asked.